The Koningshooikt—Wavre Line, abbreviated to KW Line (French: Ligne KW; Dutch: KW-stelling) and often known as the Dyle Line after the Dijle (Dyle) river, was a 60 kilometres (37 mi)-long fortified line of defence prepared by the Belgian Army between Koningshooikt (Province of Antwerp) and Wavre (Province of Brabant) which was intended to protect Brussels from a possible German invasion. Construction on the KW Line began in September 1939 after World War II had begun but while Belgium itself remained a neutral state. It was subsequently extended southwards from Wavre towards Namur (Province of Namur). The line itself consisted of bunkers, anti-tank ditches, and barricades including so-called Cointet-elements and played a key role in Allied strategy during the German invasion of Belgium in